报告题目1：Clustering in atomic nuclei: high-precision models and unusual properties

报告人：Prof. Yu. M. Tchuvil’sky (Lomonosov Moscow State University)

主持人：冯兆庆教授

报告时间：2019年11月11日 (星期一) 上午9:00

报告地点：物理楼(18号楼)二楼213室学术报告厅

报告题目2：Application of modern nuclear spectroscopy methods to study the beta-decay of atomic nuclei

报告人：Prof. I. N. Izosimov (Joint Institute for Nuclear Research, Dubna)

主持人：冯兆庆教授

报告时间：2019年11月11日 (星期一) 上午10:00

报告地点：物理楼(18号楼)二楼213室学术报告厅

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                                                  物理与光电学院

                                                                        2019年11月5日

Abstract1：The development of a microscopic theory of systems of a finite number of particles based on the first principles (ab initio approach) seems to be a task which is equally important as the advancement of theoretical physics in the direction of higher energies and small distances. A good illustration of this is the emergence of a new field of research – the physics of few-body systems – after L.D. Faddeev and O.A. Yakubovsky correctly posed the boundary-condition problem of such systems.

The central qualitative problem of systems of a finite number of particles is the explanation of structuring – the occurrence of distinguished substructures of a smaller number of particles in the system as a whole. This problem is quite adequately solved in molecular physics, where structuring is generated by the adiabaticity of the motion of nuclei with respect to the motion of electrons and the specific degeneracy of the Coulomb interaction.

The lecture discusses cluster phenomena of both classes, methods for describing them in approaches close to ab initio, far from obvious relationships between the characteristics of static and dynamic clustering, as well as other unusual properties of clustered fermion systems.

CV of Tchuvil'sky Yury. Professor Tchuvil'sky  graduated in Physics Faculty of Moscow State University in 1972. He obtained Ph.D in 1981 on the title of Microscopic description of the cluster structure of light nuclei and quark-nuclear systems and professor position at Moscow State University in 1994. Yury published about 300 papers that including Theory of clustering phenomena in the physics of atomic nuclei, cluster radioactivity and related nuclear processes, quark degrees of freedom in atomic nuclei, fundamental symmetry violation in nuclear processes and group theory and its application in nuclear physics.

Abstract2: The probability of the β-transition is proportional to the product of the lepton part described by the Fermi function f(Q_β – E) and the nucleon part described by the β transition strength function S_β(E). Information on the structure of S_β(Е) is important for many nuclear physics areas. Reliable experimental data on the structure of S_β(Е) are necessary for predicting half-lives of nuclei far from the stability line, verifying completeness of decay schemes, calculating energy release from decay of fission products in nuclear reactors, calculating spectra of delayed particles, calculating the delayed fission probability and evaluating fission barriers for nuclei far from the β-stability line, calculating production of various elements in astrophysical processes, developing microscopic models for calculation of S_β(Е), especially in deformed nuclei, and etc.

Development of experimental technique allows application of methods of nuclear spectroscopy with high energy resolution for S_β(E) fine structure measurement. Methods for investigating the structure of the strength function for the β-decay of atomic nuclei are considered and the results of measuring S_β(E) by the Total Absorption Gamma Spectroscopy and high-resolution nuclear spectroscopy techniques are presented and discussed. Emphasis is placed on investigation of the fine structure of S_β(E). Criteria for verifying the completeness of nuclear decay schemes are considered.

CV of  Igor Izosimov: Nuclear Physics and Nuclear spectroscopy – Physics faculty, Leningrad State University (St.Petersburg State University), 1977. Laser spectroscopy - Physics faculty, Leningrad State University (St.Petersburg State University), 1983. Cand. Sci. (physics) dissertation “Production of nuclei polarization and nuclear polarization coherence by tunable laser radiation”- Leningrad State University (St.Petersburg State University), 1984. Doctor of Science (physics) dissertation “Non statistical effects in nuclear reactions and nuclear decays” – V.G. Khlopin Radium Institute, 1997. Projects and technologies expert - Russian Federal Agency for Atomic Energy, 2003. Research carried and fields of scientific interest including nuclear spectroscopy, nuclear reaction at low energies, nuclear structure, non-statistical effects in nuclear reactions, gamma and beta decays, nuclear isomers, laser spectroscopy, trace analysis by nuclear and laser spectroscopy, heavy element clusters production, nuclear polarization and polarization coherence produced by laser radiation and nuclear electromagnetic moments measurements by laser spectroscopy